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arXiv · 1805.02360

The Role of Grain Boundaries under Long-Time Radiation

Yichao Zhu·Jing Luo·Xu Guo·Yang Xiang·Stephen Jonathan Chapman
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Abstract

Materials containing a high proportion of grain boundaries offer significant potential for the development of radiation-resistent structural materials. However, a proper understanding of the connection between the radiation-induced microstructural behaviour of grain boundary and its impact at long natural time scales is still missing. In this letter, point defect absorption at interfaces is summarised by a jump Robin-type condition at a coarse-grained level, wherein the role of interface microstructure is effectively taken into account. Then a concise formula linking the sink strength of a polycrystalline aggregate with its grain size is introduced, and is well compared with experimental observation. Based on the derived model, a coarse-grained formulation incorporating the coupled evolution of grain boundaries and point defects is proposed, so as to underpin the study of long-time morphological evolution of grains induced by irradiation. Our simulation results suggest that the presence of point defect sources within a grain further accelerates its shrinking process, and radiation tends to trigger the extension of twin boundary sections.

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Yichao Zhu, Jing Luo, Xu Guo, Yang Xiang, Stephen Jonathan Chapman. 2018-05-07. The Role of Grain Boundaries under Long-Time Radiation. https://doi.org/10.1103/physrevlett.120.222501

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